tape "load and save" to a PC/Mac

[Rik Bos]

> -----Oorspronkelijk bericht-----
> Van: cctalk-bounces at classiccmp.org 
> [mailto:cctalk-bounces at classiccmp.org] Namens Cameron Kaiser
> Verzonden: woensdag 18 november 2009 15:05
> Aan: cctalk at classiccmp.org
> Onderwerp: Re: tape "load and save" to a PC/Mac
> 
> > > Have people discovered any gotchas in general about using 
> PC audio 
> > > files to load and save from tape, besides the obvious ones like 
> > > don't compress, etc.? Any suggestions about how to make the Mac's 
> > > output more acceptable to the Tutor?
> > 
> > A low-pass filter?  How does the waveform look on a  'scope?
> 
> The Tutor doesn't save tape as FSK or KCS; it's actually just 
> pulses, i.e.,
> 
> -||-|--|-||-|--|--
> 
> It reminds me more of the Commodore Datasette than the Texas 
> Instruments machines the Tutor was descended from, actually.
> 
> The trick with decoding it wasn't per se figuring out the 
> frequencies, it was figuring out what pulse pattern meant 
> which bit, and then shuffling the bits around until I got 
> some sort of framing that made sense. But that's what makes 
> the playback problem mystifying because this should be very 
> simple to generate and play back. I don't see what a filter 
> would do to help here necessarily unless I'm misunderstanding 
> the alleged purpose.
> 
> --
> ------------------------------------ personal: 
> http://www.cameronkaiser.com/ --
>   Cameron Kaiser * Floodgap Systems * www.floodgap.com * 
> ckaiser at floodgap.com
> -- LOAD"STANDARD DISCLAIMER",8,1 
> ----------------------------------------------

And putting your output on a tape and trying to load that ?
Because if that's a working soluntion a filter should do something..
If there tape is generating only pulses the rise time could be affecting the
smitt trigger or other signal shaping circuit. 
Another thing, is it possible the tape set some kind of signal like write
enable or read etc.. 
And last but not least, some tape stored programs have a kind of lead-in
with enables the computer to sync on the tape signal.

-Rik